There was no specified competition.
But one thing can be easily concluded is that it's a certain amount that has to be reached then the party who just cleaned up a large amount of monster, creating safe zones and defeated the damned boss at the same time would be able to get all the points available at that one place: the stampeed from a labyrinth. Meaning, they kind of took all the chances for any other parties to have a chance. And Polaris is trying to move on as fast as possible.
Yes, it's not fully explained and frankly, that's bad writing for the drama, but it should not get this kind of reaction.
That makes no sense as an argument. The dungeon overflowing means there are more than enough monsters for both parties, especially when you ask the question of whether 1 party needs to kill most of an entire dungeon in order to rank up to the next area in the first place. And no one can ask the other party to wait 1 day for a dungeon reset if that's the case?
These 2 teams are being pitted against each other for nonsensical reasons, especially when one of them could literally say they're trying to save someone's life and time is of the essence.
As for "this kind of reaction", it's a combination of the poor writing revealed in this chapter combined with the poor writing from previous chapters where the author made bad decisions that were entirely unnecessary because, for some reason, they decided to artificially increase the drama during an event where the drama was naturally at an all-time high.
To create an analogy: Yes, our main cast was going to try to finally make it to the moon after years of making and testing prototypes... but we're going to make it even more of a drama by making the cast forget how to get off the ground despite them having reached high orbit in the last test.
It broke suspension of disbelief, and the reaction is from how much I liked this story before it literally threw away so much of what it had built up for reasons I, as someone who writes fiction, cannot fathom.
There was an ocean's worth of danger to go around, but the author decided to regress characters in order to add one cup more, contradicting lessons these characters learned just a few days or weeks prior and undermining my faith in them as characters who will actually make sense (be in-character) the next time something big happens.
It hurts because the writing and characterization before this started happening were great. I feel like the rug's been pulled out from under me.